What is a metallized polyester film capacitor？
A metallized polyester film capacitor is a type of electronic capacitor that is commonly used in various electronic circuits. It consists of a thin polyester film, which is coated with a thin layer of metal, typically aluminum, on one or both sides. This metallization process forms two electrodes that are separated by the dielectric film.
The metallization process allows for the creation of a highly compact capacitor with a large capacitance per unit volume. The capacitor is further encapsulated in a protective plastic case that also serves as an insulator.
Metallized polyester film capacitors have a number of desirable properties, including low cost, high stability, low inductance, low ESR (Equivalent Series Resistance), and high capacitance density. They are commonly used in power supplies, audio equipment, lighting circuits, and other applications where high capacitance values are needed in a small form factor.
Types of metallized polyester film capacitors
There are several types of metallized polyester film capacitors available, each with its own unique characteristics and applications. Here are some of the common types:
Miniature Metallized Polyester Film Capacitors - These capacitors are small in size and are suitable for use in a wide range of electronic circuits. They are available in a variety of capacitance values and voltage ratings.
Box Type Metallized Polyester Film Capacitors - These capacitors have a rectangular shape and are commonly used in power supplies, filters, and other high voltage applications. They are available in a range of capacitance values and voltage ratings.
Radial Lead Metallized Polyester Film Capacitors - These capacitors have a cylindrical shape and are commonly used in audio circuits and other applications where low noise and high stability are required. They are available in a range of capacitance values and voltage ratings.
Axial Lead Metallized Polyester Film Capacitors - These capacitors have a cylindrical shape and are commonly used in electronic circuits where space is limited. They are available in a range of capacitance values and voltage ratings.
Surface Mount Metallized Polyester Film Capacitors - These capacitors are designed for use in surface mount technology (SMT) applications and are available in a range of capacitance values and voltage ratings.
High Voltage Metallized Polyester Film Capacitors - These capacitors are designed for use in high voltage applications and are available in a range of capacitance values and voltage ratings. They are commonly used in power supplies, lighting circuits, and other high voltage applications.
Polarity of metallized Mylar film capacitors
Metallized polyester film capacitors are non-polarized capacitors, which means that they can be connected to a circuit in either direction without affecting their performance. This is because the dielectric material used in these capacitors is an insulating layer of polyester film that is metallized with aluminum or zinc, and the electrodes are deposited on both sides of this film.
In contrast, polarized capacitors, such as electrolytic capacitors, have a positive and negative electrode, and connecting them in reverse polarity can damage or destroy the capacitor.
Therefore, when using metallized polyester film capacitors, there is no need to worry about polarity, and they can be installed in any direction. However, it is still important to use capacitors with the correct capacitance and voltage ratings for the specific application to avoid any potential issues.
Differences between metallized polyester film capacitors and ceramic capacitors
Metallized polyester film capacitors and ceramic capacitors are both types of capacitors that are commonly used in electronic circuits. While they both serve the same function of storing electrical charge, they have different characteristics that make them suitable for different applications.
Metallized polyester film capacitors, also known as Mylar capacitors, are made by depositing a thin layer of metal, usually aluminum, onto a thin polyester film. They are available in a wide range of capacitance values, voltage ratings, and sizes, and are generally less expensive than ceramic capacitors. They have good stability and reliability, and are often used in low-cost consumer electronic products, audio equipment, and power supplies.
Ceramic capacitors are made by sandwiching a ceramic material between two metal plates. They are also available in a wide range of capacitance values, voltage ratings, and sizes, but they are generally more expensive than metallized polyester film capacitors. Ceramic capacitors have a high capacitance density, which means they can store a lot of charge in a small package. They also have a very low equivalent series resistance (ESR), which makes them suitable for high-frequency applications. Ceramic capacitors are commonly used in RF (radio frequency) circuits, filters, and decoupling applications.
In summary, metallized polyester film capacitors are a good choice for low-cost, low-frequency applications, while ceramic capacitors are better suited for high-frequency applications that require high capacitance density and low ESR. The choice of which type of capacitor to use will depend on the specific requirements of the electronic circuit being designed.
The application of metallized polyester film capacitors
Metallized polyester film capacitors, also known as metallized PET capacitors, are electronic components that are widely used in various electrical and electronic applications.
Here are some of the common applications of metallized polyester film capacitors:
Power supplies: These capacitors are often used in power supplies to filter out high-frequency noise and voltage spikes.
Lighting: They are also used in lighting applications, such as in fluorescent lamps, where they help to maintain the voltage and current levels.
Motors and generators: Metallized polyester film capacitors are used in motors and generators to improve the efficiency and power factor of the system.
Audio equipment: They are used in audio equipment, such as speakers and amplifiers, to filter out unwanted noise and improve sound quality.
Consumer electronics: Metallized polyester film capacitors are widely used in various consumer electronics, such as televisions, computers, and mobile devices, as they are cost-effective and provide reliable performance.
How does metallized polyester film capacitors work in the application?
Metallized polyester film capacitors, are a type of capacitor that uses a thin layer of polyester film as the dielectric material. The capacitor is constructed by sandwiching the polyester film between two thin layers of metal, which serve as the electrodes.
When a voltage is applied across the electrodes, an electric field is created in the dielectric material, which stores energy in the form of an electric charge. The capacitance of the capacitor is determined by the area of the electrodes, the distance between them, and the dielectric constant of the polyester film.
Metallized polyester film capacitors are commonly used in electronic circuits as they offer several advantages over other types of capacitors. They are relatively low cost, have high capacitance values, and are stable over a wide range of temperatures and frequencies. They are also non-polarized, meaning that they can be connected to a circuit without worrying about the polarity of the electrodes.
In applications such as power supplies, metallized polyester film capacitors are used to smooth out voltage fluctuations and filter out noise from the power source. They are also used in audio circuits to improve the sound quality by filtering out unwanted frequencies. In addition, they can be used as timing components in oscillator circuits, and in other applications that require a stable and reliable capacitance.
Overall, metallized polyester film capacitors are versatile components that find applications in a wide range of electrical and electronic systems.